Operating mechanism for automatic hypodermic syringes



Jan. 19, 1965 H. s. ENSTROM ETAL OPERATING MECHANISM FOR AUTOMATICHYPODERMIC SYRINGES Filed Feb. 14, 1961 Fig.1 Fig. 2

F i g. 4

I E 5 E g United States Patent 3,166,069 OPERATENG MECHANTSM FGRAUTGMATEC HYPQDEPMEQ SYRINGES Hans Gosta Enstrom, Gstertalfie, RuneGerald Fredriltsson, .larna, Rudolf A. I. Lundgren, Overenhorna, andJohn Adolf Nojd, Sodertalje, Sweden, assigners to Alrtiebolaget Astra,Apotelrarnes Kemiska Fahrilrer, Sodertalje, Sweden, a company of SwedenFiied Feb. 14, 1961, Ser. No. 39,256 Claims priority, applicationSweden, Feb. 16, 196i),

1,549/0. a 3 Claims. (4C5. 123-213) This invention deals with anoperating mechanism for automatic hypodermic syringes, that is to saysyringes where the injection occurs automatically after the mechanismhas been released so that the injection needle is brought into an activeposition and the injection fluid is squirted out through the needle.Automatic syringes are particularly intended for such civilian ormilitary use where the patient gives himself an injection.

Syringes of this type are often kept for long periods in a chargedcondition, that is to say, they are ready for immediate use. It istherefore a prerequisite thatthe releasing device provides a guaranteeagainst involuntary release as well as of satisfactory functioning whenneeded. Further it is important that after use the syringe can bereloaded in a simple way, that is to say, it must be easy to re-applythe tension so that the syringe is ready for further use when newinjection fluid is inserted,

usually in the formof a full ampoule.

The operating mechanism according to the present invention comprises aspring-driven operating device for the moving parts of the syringe, aretaining catch for holding the operating device taut, as well as anarrangement for releasing the operating mechanism from the retainingcatch, and is characterised in that it consists of at least two tonguesof a springy material running along the body of the syringe and arrangedto engage with as well as holding in a taut position, a spring-loadedrod that serves as a driving device and is arranged to move along thecentre of the syringe body, and also in that the rear end of the syringebody is provided with a release arrangement which can be movedalong thesyringe and which is arranged to engage withthe rear portions of thetongues and which, when moved towards the'body of the syringe, pressesthese tongues outwards so that they release the rod.

The invention will subsequently be described by reference to theaccompanying drawing, where FIGS. 1 and 2 show an embodiment of theinvention with FIG. 1 showing the arrangement in a loaded, secured stateand FIG. 2 showing the same arrangement where the release has justoccurred following the Withdrawal of the securing arrangement. FIGS. 3and 4 show a second embodiment, FIG. 3 in a loaded state, and FIG. 4 ina state of beginning release, analogous to FIG. 2.

The arrangement according to FIGS. 1 and 2 consists of a substantiallycylindrical portion 1 which, by means of threads 2, is designed to bescrewed into the upper end of a hypodermic syringe, which is not shown.Thus the portion 1 will constitute the rear part of the body of thesyringe.

The rear part of the member 1 is divided into a num-' ber of preferablyfour, flexible tongues 13. The tongues 3 are arranged to engage with aflange 5 on a rod 6 arranged in the cylindrical member 1, by means ofheels i3. This rod 6 is actuated by a coil-spiing 7 which endeavours topush it in the direction of the front part of the syringe. The member 1is surrounded by a cylindrical cover 8. V has projections 9 arranged toengage with the upper ends 10 of the tongues 3 and to move theseoutwards w the cover 8 is pressed down to its extreme position.

as to secure the mechanism against involuntary rele there is a resilientsplit ring 11, which is furnished v a handle 12, preferably in the formof a nylon cord ranged round the member 1 so that it rests partly aga:the lower edge of the cover '8 and partly against a 3.4 on the member 1.

When the mechanism is to be released one first p: out the ring 11 withthe aid of the handle 12. Then 1 grips the cover 8 and 'jabs or pushesthe front end of syringe against that part of the body where the injectis to be made. 7 The cover 8 'is pressed down over member 1, and theprojections 9 press the obliquely" ranged ends it) of the tongues 3outwardsrtowards inner wall of the cover 3, by which the heels 13 relethe flange 5 on the rod 6. The spring 7'n ow pushes 7 0 The inside ofthe bottom of said cover released rod 6 forward in the 'body of thesyringe wards its front part;

The events that take place in the front part of hypodermic syringe,which is not shown, will not described here since they do not constituteany p of this invention. .1

When the injection is finished and the syringe is to prepared forimmediate use the com lete operatin me anism is unscrewed from the frontpart of the body the syringe and the securing ring is replaced, and thec spring is compressed by pressing inthe rod 6 until a cl is heard. Nospecial tool is required for this operatil but the rod can simply bepressed against a table, 3 instance, until it reaches the securedpositionillustrai in FIG. 1, where the lower end of the rod reaches sonwhat beyond the threaded portion of the cylindrical p tion 1. Thereafterthe operating mechanism is screvs into an already prepared front partand the syringe again ready for use. 7

The device of FIGS. 3 and 4 differs from that of PK 1 and 2 only asregards the cover, designated 19 in PK 3 and 4. The cylindrical portionof the cover is clos at its top bya member 13 which'is provided with p]jecting portions 17, arranged to engage with theup; portions 15 of thespringy tongues which hold the sprir loaded rod in a taut position. Theupper portion of t wall of the cylindrical cover 19 has a thinnerportion 1 The space between said portion 16 and the projectio 17 is sowide that the tongue portions 15 can enter in said space withoutchanging their upward-outward dire tion. Compare with the embodiment ofFlGS. 1 and where the tongue portion 1 must be bent from the po tion ofFIG. 1 into the position of FIG. 2 when t mechanism is to be released. 7

What is claimed is: g 1. An operating -mechanism for an automatic hypdermic syringe of the type including a spring-driven o crating devicefor the moving parts of the syringe,- retaining catch for holding theoperating device star and an arrangement for releasing the operating mecanism from the retaining catch, characterized in th said mechanismcomprises a generally cylindrical hollc body the same being at one endthereof threaded to ma a threaded end of such syringe, a coil spring andan a tuating rod within the coil thereof, said coil spring at actuatingrod being disposed within said hollow bod 7 said actuating rod beingprovided with a shoulder at tl 'rear end of the same which is remotefrom said threadt portion, a plurality of resilient tongues extendingfro and, mounted on said hollow body rearwardly with r spectto saidthreaded portion and surrounding the a jacent rear portions of saidactuating rod and coil sprin said tongues, being interiorlyprovidedrwitha first shou I der constituting a support for'therear endof saidcc der of said operating rod to hold the operating rodring-loaded position, a release arrangement movable said hollow body andadapted to engage said dered tongue and which, when moved toward the dedend of said body, presses said shouldered tongue and with a secondshoulder engaging the said with respect to said threaded portion andsurrounding the adjacent rear portions of said actuating rod and coilspring, said tongues being interiorly provided with a first shoulderconstituting a support for the rear end of said coil spring and with asecond shoulder engaging the said shoulder of said operating rod to holdthe operating rod in spring-loaded position, a release arrangementmovable along said hollow body and adapted to engage said shoulderedtongue and which, when moved toward the threaded end of said body,presses said shouldered tongue outwardly so as to release saidspring-loaded actuating rod from said tongues, and latch means rengdevice for the moving parts of the syringe, a

ning catch for holding the operating device taut, an arrangement forreleasing the operating mechn from the retaining catch, characterized inthat mechanism comprises'a generally cylindrical hollow the same beingat one end thereof threaded to mate readed end of such syringe, acoilspring and an iting rod within the coil thereof, said coil springactuating rod being disposed within said hollow body, actuating rodbeing provided with a shoulder at rear end of the same'which is' remotefrom said tded portion, a plurality of resilient tongues extendfrom andmounted on said hollow body rearwardly movably inactivating said Arelease, arrangement.

References Cited by the Examiner UNITED STATES PATENTS 2,676,591 4/54FOX 128-216 7 2,832,339 4/58 Sarnoffetal 12s- 21s 3,066,670 12/62Stauifer.

FOREIGN PATENTS 331,375 1/59 Switzerland.

RICHARD. A. GAUDET, Primary Examiner.

JORDAN FRANKLIN, RICHARD J. HOFFMAN,

I Examiners.

1. AN OPERATING MECHANISM FOR AN AUTOMATIC HYPODERMIC SYRINGE OF THETYPE INCLUDING A SPRING-DRIVEN OPERATING DEVICE FOR THE MOVING PARTS OFTHE SYRINGE, A RETAINING CATCH FOR HOLDING THE OPERATING DEVICE TAUT,AND AN ARRANGEMENT FOR RELEASING THE OPENING MECHANISM FROM THERETAINING CATCH, CHARACTERIZED IN THAT SAID MECHANISM COMPRISES AGENERALLY CYLINDRICAL HOLLOW BODY THE SAME BEING AT ONE END THEREOFTHREADED TO MATE A THREADED END OF SUCH SYRINGE, A COIL SPRING AND ANACTUATING ROD WITHIN THE COIL THEREOF, SAID COIL SPRING AND ACTUATINGROD BEING DISPOSED WITHIN SAID HOLLOW BODY, SAID ACTUATING ROD BEINGPROVIDED WITH A SHOULDER AT THE REAR END OF THE SAME WHICH IS REMOTEFROM SAID THREADED PORTION, A PLURALITY OF RESILIENT TONGUES EXTENDINGFROM AND MOUNTED ON SAID HOLLOW BODY REARWARDLY WITH RESPECT TO SAIDTHREADED PORTION AND SURROUNDING THE ADJACENT REAR PORTIONS OF SAIDACTUATING ROD AND COIL SPRING, SAID TONGUES BEING INTERIORLY PROVIDEDWITH A FIRST SHOULDER CONSTITUTING A SUPPORT FOR THE REAR END OF SAIDCOIL SPRING AND WITH A SECOND SHOULDER ENGAGING THE SAID SHOULDER OFSAID OPERATING ROD TO HOLD THE OPERATING ROD IN SPRING-LOADED POSITION,A RELEASE ARRANGEMENT MOVABLE ALONG SAID HOLLOW BODY AND ADAPTED TOENGAGE SAID SHOULDERED TONGUE AND WHICH, WHEN MOVED TOWARD THE THREADEDEND OF SAID BODY, PRESSES SAID SHOULDER TONGUE OUTWARDLY SO AS TORELEASE SAID SPRING-LOADED ACTUATING ROD FROM SAID TONGUES.